ASTM D2488-17e1

Standard Practice for Description and Identification of Soils (Visual-Manual Procedures)

SIGNIFICANCE AND USE
5.1 The descriptive information required in this practice can be used to describe a soil to aid in the evaluation of its significant properties for engineering use.  
5.2 The descriptive information required in this practice should be used to supplement the classification of a soil as determined by Test Method D2487.  
5.3 This practice may be used in identifying soils using the classification group symbols and names as prescribed in Test Method D2487. Since the names and symbols used in this practice to identify the soils are the same as those used in Test Method D2487, it shall be clearly stated in reports and all other appropriate documents, that the classification symbol and name are based on visual-manual procedures.  
5.4 This practice is to be used for identification of soils in the field, laboratory, or any other location where soil samples are inspected and described.  
5.5 This practice may be used to group similar soil samples to reduce the number of laboratory tests necessary for positive soil classification.
Note 2: The ability to describe and identify soils correctly is learned more readily under the guidance of experienced personnel, but it may also be acquired systematically by comparing numerical laboratory test results for typical soils of each type with their visual and manual characteristics.  
5.6 Soil samples from a given boring, test pit or location which appear to have similar characteristics are not required to follow all of the procedures in this practice, providing at least one sample is completely described and identified. These samples may follow only the necessary procedures to determine they are “similar” and shall be labeled as such.  
5.7 This practice may be used in combination with Practice D4083 when working with frozen soils.
Note 3: The quality of the result produced by this standard is dependent on the competence of the personnel performing it and the suitability of the equipment and facilities used. Agencies that mee...
SCOPE
1.1 This practice covers procedures for the description of soils for engineering purposes.  
1.2 This practice also describes a procedure for identifying soils, at the option of the user, based on the classification system described in Test Method D2487. The identification is based on visual examination and manual tests. It shall be clearly stated in reporting, the soil identification is based on visual-manual procedures.  
1.2.1 When precise classification of soils for engineering purposes is required, the procedures outlined in Test Method D2487 shall be used.  
1.2.2 In this practice, the identification procedures assigning a group symbol and name are limited to soil particles smaller than 3 in. (75 mm).  
1.2.3 The identification portion of this practice is limited to naturally occurring soils. Specimens used for identification may be either intact or disturbed.  
Note 1: This practice may be used as a descriptive system applied to such materials as shale, claystone, shells, crushed rock, etc. (see Appendix X2).  
1.3 The descriptive information in this practice may be used with other soil classification systems or for materials other than naturally occurring soils.  
1.4 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are rationalized conversions to SI units that are provided for information only and are not considered standard. The sieve designations are identified using the “alternative” system in accordance with Practice E11.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements see Section 8.  
1.6 This practice offers a set of instructions for performing one or...

General Information

• Status: Published
• Publication Date: 14-Jul-2017
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.07 - Identification and Classification of Soils

Relations

• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM D2487-17e1 - Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
• Effective Date: 15-Dec-2017
• Refers: ASTM D2487-17 - Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
• Effective Date: 15-Dec-2017
• Refers: ASTM D4427-13(2017) - Standard Classification of Peat Samples by Laboratory Testing
• Effective Date: 01-May-2017
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM E11-13 - Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves
• Effective Date: 01-Oct-2013
• Refers: ASTM D4427-13 - Standard Classification of Peat Samples by Laboratory Testing
• Effective Date: 01-Jul-2013
• Refers: ASTM D1587-08(2012)e1 - Standard Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes
• Effective Date: 15-May-2012
• Refers: ASTM D3740-12a - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-May-2012
• Refers: ASTM D3740-12 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Mar-2012
• Refers: ASTM D1586-11 - Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of Soils
• Effective Date: 01-Nov-2011
• Refers: ASTM D653-11 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Sep-2011
• Refers: ASTM D3740-11 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Sep-2011
• Refers: ASTM D2487-11 - Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
• Effective Date: 01-May-2011

Overview

ASTM D2488-17e1 is a widely recognized standard practice developed by ASTM International for the description and identification of soils using visual-manual procedures. This standard provides essential guidelines for visually and manually classifying soil samples, particularly in field and laboratory settings, to support engineering and geotechnical projects. The practice enhances the reliability of soil descriptions and helps professionals make informed decisions about soil properties and their suitability for construction, environmental, and land development applications.

Visual-manual soil descriptions are especially valuable when immediate results are required or when laboratory testing is limited, making ASTM D2488-17e1 an indispensable tool in geotechnical site investigations.

Key Topics

• Scope and Application: ASTM D2488-17e1 outlines procedures for describing and identifying natural soil samples (both intact and disturbed) based on visual observation and simple manual tests. It applies to soil particles smaller than 3 inches and can be used in the field, laboratory, or other locations.
• Descriptive Criteria: The standard emphasizes description of properties such as soil color, moisture condition, grain size distribution (gravel, sand, fines), particle shape and angularity, presence of organic materials, odor, structure, consistency, and cementation.
• Identification Procedures: Group symbols and names are assigned following the Unified Soil Classification System (USCS) as per ASTM D2487, with the requirement that visual-manual identification is clearly stated in documentation.
• Supplementing Laboratory Testing: Visual-manual procedures are used to group similar soil samples, reducing the number of laboratory tests required for positive classification and enhancing cost-efficiency.
• Reporting and Safety: The standard sets guidelines for sample identification, documentation, and safety precautions, especially when handling chemicals such as hydrochloric acid.

Applications

ASTM D2488-17e1 is applied in a variety of geotechnical and civil engineering contexts, including:

• Site Investigations: Field professionals use the standard’s visual-manual methods to rapidly assess soil conditions, supporting timely decision-making for construction, infrastructure development, and foundation design.
• Soil Sampling for Engineering Projects: Laboratories and field teams use this practice to describe and preliminarily classify soils prior to or in conjunction with laboratory-based classification methods.
• Environmental Assessments: Accurate identification of soil properties is essential for environmental site characterization, remediation, and risk assessment.
• Construction Quality Control: Contractors and inspectors rely on standardized soil descriptions to ensure material suitability and monitor site conditions during construction projects.
• Supplement to USCS: The practice complements more precise, laboratory-based USCS soil classification (ASTM D2487) by providing a cost-effective, rapid preliminary identification method that can guide further testing.

Related Standards

Professionals applying ASTM D2488-17e1 often reference related ASTM standards to achieve comprehensive soil characterization and quality assurance:

• ASTM D2487 – Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System): For laboratory-based soil classification.
• ASTM D653 – Terminology Relating to Soil, Rock, and Contained Fluids: Provides essential definitions used throughout soil mechanics standards.
• ASTM D1452 – Practice for Soil Exploration and Sampling by Auger Borings.
• ASTM D1586 – Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of Soils.
• ASTM D1587 – Practice for Thin-Walled Tube Sampling of Fine-Grained Soils for Geotechnical Purposes.
• ASTM D3740 – Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock.
• ASTM D4083 – Practice for Description of Frozen Soils (Visual-Manual Procedure): For working with frozen soil samples.
• ASTM E11 – Specification for Woven Wire Test Sieve Cloth and Test Sieves.

Practical Value

ASTM D2488-17e1 empowers geotechnical engineers, soil technicians, and construction professionals to establish a standardized, reliable baseline for soil characterization. Its use ensures consistent communication, effective documentation, and informed engineering judgment across diverse project types, supporting better outcomes in design, construction, and environmental management.

Keywords: ASTM D2488, soil identification, soil description, visual-manual procedures, soil classification, Unified Soil Classification System, USCS, field soil testing, geotechnical engineering, soil properties.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
´1
Designation:D2488 −17
Standard Practice for
Description and Identification of Soils (Visual-Manual
Procedures)
This standard is issued under the fixed designation D2488; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Editorially corrected Fig. 2 in March 2018.
1. Scope* responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 This practice covers procedures for the description of
mine the applicability of regulatory limitations prior to use.
soils for engineering purposes.
For specific precautionary statements see Section 8.
1.2 This practice also describes a procedure for identifying
1.6 This practice offers a set of instructions for performing
soils, at the option of the user, based on the classification
one or more specific operations. This document cannot replace
system described in Test Method D2487. The identification is
education or experience and should be used in conjunction
based on visual examination and manual tests. It shall be
with professional judgment. Not all aspects of this practice may
clearly stated in reporting, the soil identification is based on
be applicable in all circumstances. This ASTM standard is not
visual-manual procedures.
intended to represent or replace the standard of care by which
1.2.1 When precise classification of soils for engineering
the adequacy of a given professional service must be judged,
purposes is required, the procedures outlined in Test Method
nor should this document be applied without consideration of
D2487 shall be used.
a project’s many unique aspects. The word “Standard” in the
1.2.2 Inthispractice,theidentificationproceduresassigning
title of this document means only that the document has been
a group symbol and name are limited to soil particles smaller
approved through the ASTM consensus process.
than 3 in. (75 mm).
1.7 This international standard was developed in accor-
1.2.3 The identification portion of this practice is limited to
dance with internationally recognized principles on standard-
naturally occurring soils. Specimens used for identification
ization established in the Decision on Principles for the
may be either intact or disturbed.
Development of International Standards, Guides and Recom-
NOTE 1—This practice may be used as a descriptive system applied to
mendations issued by the World Trade Organization Technical
suchmaterialsasshale,claystone,shells,crushedrock,etc.(seeAppendix
Barriers to Trade (TBT) Committee.
X2).
1.3 The descriptive information in this practice may be used
2. Referenced Documents
withothersoilclassificationsystemsorformaterialsotherthan
2.1 ASTM Standards:
naturally occurring soils.
D653 Terminology Relating to Soil, Rock, and Contained
1.4 Units—The values stated in inch-pound units are to be
Fluids
regarded as standard. The values given in parentheses are
D1452 Practice for Soil Exploration and Sampling byAuger
rationalized conversions to SI units that are provided for
Borings
information only and are not considered standard. The sieve
D1586 Test Method for Standard PenetrationTest (SPT) and
designations are identified using the “alternative” system in
Split-Barrel Sampling of Soils
accordance with Practice E11.
D1587 Practice for Thin-Walled Tube Sampling of Fine-
Grained Soils for Geotechnical Purposes
1.5 This standard does not purport to address all of the
D2113 Practice for Rock Core Drilling and Sampling of
safety concerns, if any, associated with its use. It is the
Rock for Site Exploration
This practice is under the jurisdiction of ASTM Committee D18 on Soil and
Rock and is the direct responsibility of Subcommittee D18.07 on Identification and
Classification of Soils. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 15, 2017. Published August 2017. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1966. Last previous edition approved in 2009 as D2488 – 09a. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D2488-17E01. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
D2488−17
D2487 Practice for Classification of Soils for Engineering 3.1.9.3 fine—passes a No. 40 (425-µm) sieve and is retained
Purposes (Unified Soil Classification System) on a No. 200 (75-µm) sieve.
D3740 Practice for Minimum Requirements for Agencies
3.1.10 silt—soil passing a No. 200 (75-µm) sieve that is
Engaged in Testing and/or Inspection of Soil and Rock as
nonplastic or very slightly plastic and that exhibits little or no
Used in Engineering Design and Construction
strength when air dry. For classification, a silt is a fine-grained
D4083 Practice for Description of Frozen Soils (Visual-
soil, or the fine-grained portion of a soil, with a plasticity index
Manual Procedure)
less than 4, or the plot of plasticity index versus liquid limit
D4427 Classification of Peat Samples by Laboratory Testing
falls below the “A” line (see Fig. 4 of Test Method D2487).
E11 Specification for Woven Wire Test Sieve Cloth and Test
3.1.11 fine-grained soils—soils that are made up of 50 % or
Sieves
more particles that will pass a No. 200 (75 µm) sieve.
3. Terminology
3.1.12 coarse-grained soils—soils that are made up of more
than 50 % particles that will be retained on a No. 200 (75 µm)
3.1 Definitions:
sieve.
3.1.1 For definitions of common technical terms in this
standard, refer to Terminology D653.
4. Summary of Practice
3.1.2 cobbles—particles of rock that will pass a 12-in.
4.1 Using visual examination and simple manual tests, this
(300-mm) square opening and be retained on a 3-in. (75-mm)
practice gives standardized criteria and procedures for describ-
sieve.
ing and identifying soils.
3.1.3 boulders—particles of rock that will not pass a 12-in.
(300-mm) square opening. 4.2 The soil can be given an identification by assigning a
groupsymbol(s)andname.Theflowcharts,Fig.1aandFig.1b
3.1.4 clay—soil passing a No. 200 (75-µm) sieve that can be
for fine-grained soils, and Fig. 2, for coarse-grained soils, can
made to exhibit plasticity (putty-like properties) within a range
be used to assign the appropriate group symbol(s) and name. If
of water contents, and that exhibits considerable strength when
the soil has properties which do not distinctly place it into a
air-dried. For classification, a clay is a fine-grained soil, or the
specific group, borderline symbols may be used, see Appendix
fine-grained portion of a soil, with a plasticity index equal to or
X3.
greater than 4, and the plot of plasticity index versus liquid
limit falls on or above the “A” line (see Fig. 4 of Test Method
5. Significance and Use
D2487).
5.1 The descriptive information required in this practice can
3.1.5 gravel—particles of rock that will pass a 3-in. (75-
be used to describe a soil to aid in the evaluation of its
mm) sieve and be retained on a No. 4 (4.75-mm) sieve with the
significant properties for engineering use.
following subdivisions:
5.2 The descriptive information required in this practice
3.1.5.1 coarse—passesa3-in.(75-mm)sieveandisretained
should be used to supplement the classification of a soil as
on a ⁄4-in. (19-mm) sieve.
determined by Test Method D2487.
3.1.5.2 fine—passes a ⁄4-in. (19-mm) sieve and is retained
5.3 This practice may be used in identifying soils using the
on a No. 4 (4.75-mm) sieve.
classification group symbols and names as prescribed in Test
3.1.6 organic clay—a clay with sufficient organic content to
Method D2487. Since the names and symbols used in this
influence the soil properties. For classification, an organic clay
practice to identify the soils are the same as those used in Test
is a soil that would be classified as a clay, except that its liquid
Method D2487, it shall be clearly stated in reports and all other
limitvalueafterovendryingislessthan75 %ofitsliquidlimit
appropriatedocuments,thattheclassificationsymbolandname
value before oven drying.
are based on visual-manual procedures.
3.1.7 organic silt—a silt with sufficient organic content to
5.4 This practice is to be used for identification of soils in
influence the soil properties. For classification, an organic silt
the field, laboratory, or any other location where soil samples
is a soil that would be classified as a silt except that its liquid
are inspected and described.
limitvalueafterovendryingislessthan75 %ofitsliquidlimit
5.5 This practice may be used to group similar soil samples
value before oven drying.
to reduce the number of laboratory tests necessary for positive
3.1.8 peat—a soil composed primarily of vegetable tissue in
soil classification.
various stages of decomposition usually with an organic odor,
a dark brown to black color, a spongy consistency, and a
NOTE 2—The ability to describe and identify soils correctly is learned
more readily under the guidance of experienced personnel, but it may also
texture ranging from fibrous to amorphous.
be acquired systematically by comparing numerical laboratory test results
3.1.9 sand—particles of rock that will pass a No. 4 (4.75-
for typical soils of each type with their visual and manual characteristics.
mm) sieve and be retained on a No. 200 (75-µm) sieve with the
5.6 Soil samples from a given boring, test pit or location
following subdivisions:
which appear to have similar characteristics are not required to
3.1.9.1 coarse—passes a No. 4 (4.75-mm) sieve and is
follow all of the procedures in this practice, providing at least
retained on a No. 10 (2.00-mm) sieve.
one sample is completely described and identified. These
3.1.9.2 medium—passes a No. 10 (2.00-mm) sieve and is samples may follow only the necessary procedures to deter-
retained on a No. 40 (425-µm) sieve. mine they are “similar” and shall be labeled as such.
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D2488−17
NOTE—Percentages are based on estimating amounts of fines, sand, and gravel to the closest 5 %.
FIG. 1a Flow Chart for Identifying Inorganic Fine-Grained Soil (50% or more fines)
NOTE—Percentages are based on estimating amounts of fines, sand, and gravel to the closest 5 %.
FIG. 1b Flow Chart for Identifying Organic Fine-Grained Soil (50% or more fines)
5.7 This practice may be used in combination with Practice 6.3 Jar with Lid (optional)
D4083 when working with frozen soils.
6.4 Hand Lens (optional)
NOTE 3—The quality of the result produced by this standard is
6.5 Shallow Pan (optional)
dependent on the competence of the personnel performing it and the
suitability of the equipment and facilities used. Agencies that meet the
7. Reagents
criteria of Practice D3740 are generally considered capable of competent
and objective testing/sampling/inspection/etc. Users of this standard are
7.1 Purity of Water—Unless otherwise indicated, references
cautioned that compliance with Practice D3740 does not in itself assure
to water shall be understood to mean water from a city water
reliable results. Reliable results depend on many factors; Practice D3740
supply or natural source, including non-potable water.
provides a means of evaluating some of those factors.
7.2 Hydrochloric Acid—A small bottle of dilute hydrochlo-
6. Apparatus
ric acid (HCl) one part HCl (10 N) to three parts distilled water
6.1 Small Knife or Spatula
(Thisreagentisoptionalforusewiththispractice).SeeSection
6.2 Test Tube and Stopper (optional) 8.
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D2488−17
NOTE—Percentages are based on estimating amounts of fines, sand, and gravel to the closest 5 %.
NOTE—It is suggested that a distinction be made between dual symbols and borderline symbols.
Dual Symbol—A dual symbol is two symbols separated by a hyphen, for example, GP-GM, SW-SC, CL-ML used to indicate that the soil has been identified as having
the properties of a classification in accordance with Test Method D2487 where two symbols are required. Two symbols are required when the soil has between 5 and 12 %
fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart.
Borderline Symbol—A borderline symbol is two symbols separated by a slash, for example, CL/CH, GM/SM, CL/ML. A borderline symbol should be used to indicate that
the soil has been identified as having properties that do not distinctly place the soil into a specific group (see Appendix X3).
FIG. 2Flow Chart for Identifying Coarse-Grained Soils (less than 50% fines)
geologic stratum, a pedologic horizon or a location description with
8. Safety Precautions
respect to a permanent monument, a grid system or a station number and
8.1 When preparing the dilute HCl solution of one part
offset with respect to a stated centerline and a depth or elevation.
concentrated hydrochloric acid (10 N) to three parts of distilled
9.3 For accurate description and identification, the mini-
water, slowly add acid into water following necessary safety
mum amount of the specimen to be examined shall be in
precautions. Handle with caution, utilize personal protective
accordance with Table 1.
equipment and store safely. If solution comes into contact with
NOTE 6—If random isolated particles are encountered that are signifi-
the skin or eyes, rinse thoroughly with water.
cantly larger than the particles in the soil matrix, the soil matrix can be
8.2 Caution—Acid shall be added to the water. Do not add
accuratelydescribedandidentifiedinaccordancewiththeprecedingtable.
water to the acid as this may cause an adverse reaction.
9.4 If the sample or specimen being examined is smaller
than the minimum recommended specimen size, the report
9. Sampling
shall include a remark stating as such.
9.1 The sample shall be considered to be representative of
the stratum from which it was obtained by an appropriate,
accepted, or standard procedure.
TABLE 1 Minimum Specimen Dry Mass Requirements
Maximum Particle Minimum Specimen
NOTE 4—Preferably, the sampling procedure should be identified as
Size, Sieve Opening Size, by Dry Mass
having been conducted in accordance with Practices D1452, D1587,or
No. 4 (4.75 mm) 0.25 lb (110 g)
D2113, or Test Method D1586.
⁄8 in. (9.5 mm) 0.5 lb (220 g)
9.2 The sample shall be carefully identified as to origin. ⁄4 in. (19.0 mm) 2.2 lb (1.0 kg)
1 ⁄2 in. (38.1 mm) 18 lb (8.0 kg)
NOTE 5—Remarks as to the origin may take the form of a boring 3 in. (75.0 mm) 132 lb (60.0 kg)
number and sample number in conjunction with a project number, a
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D2488−17
10. Descriptive Information for Soils 10.8 Cementation—Describe the cementation of intact
coarse-grained soils as weak, moderate, or strong, in accor-
10.1 Angularity—Describe the angularity of the sand
dance with the criteria in Table 7.
(coarse sizes only), gravel, cobbles, and boulders, as angular,
subangular, subrounded, or rounded in accordance with the
10.9 Structure—Describe the structure of intact soils in
criteria in Table 2 and Fig. 3. A range of angularity may be
accordance with the criteria in Table 8.
stated, such as: subrounded to rounded.
10.10 Range of Particle Sizes—For gravel and sand
10.2 Shape—Describe the shape of the gravel, cobbles, and
components, describe the range of particle sizes within each
boulders as flat, elongated, or flat and elongated if they meet
component as defined in 3.1.5 and 3.1.9. For example, about
thecriteriainTable3andFig.4.Otherwise,donotmentionthe
20 % fine to coarse gravel, about 40 % fine to coarse sand.
shape. Indicate the fraction of the particles that have the shape,
10.11 Maximum Particle Size—Describe the maximum par-
such as: one-third of the gravel particles are flat.
ticle size found in the sample in accordance with the following
10.3 Color—Describe the color. Color is an important
information:
property in identifying organic soils, and within a given
10.11.1 Sand Size—If the maximum particle size is a sand
locality it may also be useful in identifying materials of similar
size, describe as fine, medium, or coarse as defined in 3.1.9.
geologic origin. If the sample contains layers or patches of
For example: maximum particle size, medium sand.
varying colors, this shall be noted and all representative colors
10.11.2 Gravel Size—If the maximum particle size is a
shall be described. The color shall be described for moist
gravel size, describe the maximum particle size as the smallest
samples. If the color represents a dry condition, this shall be
sieve opening that the particle will pass. For example, maxi-
stated in the report.
1 1
mum particle size, 1 ⁄2 in. will pass a 1 ⁄2-in. (square opening)
10.4 Odor—Describe the odor if organic or unusual.
but not a ⁄4-in. (square opening).
10.4.1 Soils containing a significant amount of organic
10.11.3 Cobble or Boulder Size—If the maximum particle
materialusuallyhaveadistinctiveodorofdecayingvegetation.
size is a cobble or boulder size, describe the maximum
This is especially apparent in fresh samples.
dimension of the largest particle. For example: maximum
10.4.2 If the samples are dried, the odor may often be
dimension, 18 in. (450 mm).
revived by moistening the sample and slightly heating it.
10.12 Hardness—Describe the hardness of coarse sand and
10.4.3 Odors from petroleum products, chemicals or other
larger particles as hard, or state what happens when the
substances shall be described.
particlesarehitbyahammer,forexample,gravel-sizeparticles
10.4.4 Some fumes emitting from soil samples, especially
fracture with considerable hammer blow, some gravel-size
of a chemical nature, may pose a health risk. Proper safety
particles crumble with hammer blow. “Hard” means particles
protocols which may include the use of personal protective
do not crack, fracture, or crumble under a hammer blow.
equipment must be followed in these instances. It is the
responsibility of the user to determine the extent of the health
10.13 Additional comments shall be noted, such as the
risk and the correct protocols to follow.
presence of roots or root holes, difficulty in drilling or augering
the hole, caving of the trench or hole, or the presence of mica.
10.5 Moisture Condition—Describe the moisture condition
as dry, moist, or wet, in accordance with the criteria in Table 4.
10.14 A local or commercial name or a geologic interpre-
tation of the soil, or both, may be added if identified as such.
10.6 HCl Reaction—Describe the reaction with HCl as
none, weak, or strong, in accordance with the criteria in Table
10.15 A classification or identification of the soil in accor-
5. Since calcium carbonate is a common cementing agent, a
dance with other classification systems may be added if
comment of its presence on the basis of the reaction with dilute
identified as such.
hydrochloric acid is important.
10.7 Consistency—For intact fine-grained soil, describe the 11. Identification of Peat
consistency as very soft, soft, firm, hard, or very hard, in
11.1 A sample composed primarily of vegetative tissue in
accordance with the criteria in Table 6. This observation is
various stages of decomposition that has a fibrous to amor-
inappropriate for soils with significant amounts of gravel.
phous texture, usually a dark brown to black color, and an
organic odor, shall be designated as highly organic and shall be
identifiedaspeat,PT.Peatsamplesshallnotbesubjectedtothe
identification procedures described hereafter. Refer to D4427
TABLE 2 Criteria for Describing Angularity of Coarse-Grained
for procedures on classifying peat.
Particles (see Fig. 3)
Description Criteria
12. Preparation for Identification
Angular Particles have sharp edges and relatively plane sides with
unpolished surfaces
12.1 The soil identification portion of this practice is based
Subangular Particles are similar to angular description but have rounded
edges on the portion of the soil sample that will pass a 3-in. (75-mm)
Subrounded Particles have nearly plane sides but have well-rounded
sieve. The larger than 3-in. (75-mm) particles must be
corners and edges
removed, manually for a loose sample, or ignored for an intact
Rounded Particles have smoothly curved sides and no edges
sample before classifying the soil.
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D2488−17
FIG. 3 Typical Angularity of Bulky Grains
TABLE 3 Criteria for Describing Particle Shape (see Fig. 4)
that the report state that the percentages of cobbles and boulders are by
volume.
The particle shape shall be described as follows where length, width, and
thickness refer to the greatest, intermediate, and least dimensions of a particle,
12.3 Of the fraction of the soil smaller than 3 in. (75 mm),
respectively.
estimate and note the percentage, by dry mass, of the gravel,
Flat Particles with width/thickness > 3
sand, and fines (see Appendix X4 for suggested procedures).
Elongated Particles with length/width > 3
Flat and Particles meet criteria for both flat and elongated
NOTE 8—Since the particle-size components appear visually on the
elongated
basis of volume, considerable experience is required to estimate the
percentages on the basis of dry mass. Frequent comparisons with
laboratory particle-size analyses should be made.
12.2 Estimate and note the percentage of cobbles and the 12.3.1 Thepercentagesshallbeestimatedtotheclosest5 %.
percentage of boulders. Visual estimates will be based on the The percentages of gravel, sand, and fines must add up to
100 %.
percentage by volume.
12.3.2 If one of the components is present but not in
NOTE 7—Since the percentages of the particle-size distribution in Test
sufficient quantity to be considered 5 % of the smaller than
Method D2487 are by dry mass, and the estimates of percentages for
gravel, sand, and fines in this practice are by dry mass, it is recommended 3-in. (75-mm) portion, indicate its presence by the term trace,
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D2488−17
TABLE 7 Criteria for Describing Cementation
Description Criteria
Weak Crumbles or breaks with handling or little finger pressure
Moderate Crumbles or breaks with considerable finger pressure
Strong Will not crumble or break with finger pressure
TABLE 8 Criteria for Describing Structure
Description Criteria
Stratified Alternating layers of varying material or color with layers at
least ⁄4 in. (6 mm) thick; note thickness
Laminated Alternating layers of varying material or color with the layers
less than 6 mm thick; note thickness
Fissured Breaks along definite planes of fracture with little resistance to
fracturing
Slickensided Fracture planes appear polished or glossy, sometimes striated
Blocky Cohesive soil that can be broken down into small angular
lumps which resist further breakdown
Lensed Inclusion of small pockets of different soils, such as small
lenses of sand scattered through a mass of clay; note
thickness
Homogeneous Same color and appearance throughout
13. Preliminary Identification
13.1 The soil is fine grained if it contains 50 % or more
fines. Follow the procedures for identifying fine-grained soils
in Section 14.
13.2 Thesoilis coarse grainedifitcontainsmorethan50 %
coarse-grained soils. Follow the procedures for identifying
coarse-grained soils in Section 15.
14. Procedure for Identifying Fine-Grained Soils
14.1 Select a representative sample of the material for
examination.RemoveparticleslargerthantheNo.40(425µm)
sieve (medium sand and larger) until a specimen equivalent to
FIG. 4 Criteria for Particle Shape
about a handful of material is available. Use this specimen for
performing the dry strength, dilatancy, and toughness tests.
TABLE 4 Criteria for Describing Moisture Condition
Description Criteria
14.2 Dry Strength:
Dry Absence of moisture, dusty, dry to the touch
14.2.1 From the specimen, select enough material to mold
Moist Damp but no visible water
into a ball about 1 in. (25 mm) in diameter. Mold the material
Wet Visible free water, usually soil is below water table
until it has the consistency of putty, adding water if necessary.
14.2.2 From the molded material, make at least three test
TABLE 5 Criteria for Describing the Reaction with HCl specimens.Atest specimen shall be a ball of material about ⁄2
in. (12 mm) in diameter.Allow the test specimens to air dry or
Description Criteria
None No visible reaction
dry by artificial means, with a temperature not to exceed 140°F
Weak Some reaction, with bubbles forming slowly
(60°C).
Strong Violent reaction, with bubbles forming immediately
14.2.3 If the
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